The present invention relates to a waveguide filter having a stepped transformer area on the input side and/or output side as well as an area of alternate-height waveguide segments.
A waveguide filter of this type is known from "Microwave Filters, Impedance-Matching Networks and Coupling Structures"; Matthaei, Young, Jones; McGraw Hill Book Company 1964, pages 398 to 408, in particular FIG. 7.05-8 on page 405. The area of alternate-height waveguide segments in this filter has a waffle-iron filter structure. On the input and output sides of this structure are located stepped transformers with corrugated areas that each measure .lambda..sub.g /4 in length, where .lambda.k represents the waveguide wavelength in the pass band.
A waveguide filter with stepped transformers on the input and output sides as well as an intermediate area of coupled resonators in the form of a corrugated waveguide filter (Matthaei, Young, Jones, page 358, paragraph 2) with low-pass action is known from ANT Nachrichtentechnische Berichte, Volume 5, November 1988, pages 114 to 120.